Error in Altiris Agent log, "Error activating agent session 0: Class not registered"
search cancel

Error in Altiris Agent log, "Error activating agent session 0: Class not registered"


Article ID: 176563


Updated On:


IT Management Suite


After the Altiris Agent has been installed (manually or via a Notification Server push) the agent will not load or start. The only real contents in the agent logs are the following two error entries:

Error starting service: Error starting dispatcher: The service process could not connect to the service controller. (-2147023833)

Error activating agent session 0: Class not registered (-2147221164)

There are no visible signals that the installation failed except that in .\Windows\System32\AeXNSC.log, it has a single failure line:

WARNING! Failed to register one or more agent components.

This failure is eventually returned to, and reflected in .\Windows\AeXSWDInstSvc.log and is ultimately reported as a complete install failure.

Sometimes (but not always) the operating system returned the following error in the event logs:

The Altiris Agent service failed to start due to the following error: Altiris Agent is not a valid Win32 application.

If the event logs show nothing, it can be a miserable experience trying to figure out what really failed and why. The only item missing that would indicate that the Altiris Agent installation had failed (other than the error logs) is that the following key and its subcomponents were not added to the registry to allow the agent to start as a service:



The local OS is unable to start AeXNSAgent.exe, via Services Manager, from a path that has spaces in it such as .\Program Files\Altiris\Altiris Agent\AeXNSAgent.exe. 

The ImagePath string value under HKLM/System/CurrentControlSet/Services/AeXNSClient, does call AeXNSAgent.exe from the previous path.

This is ultimately an MS issue, often seen when a computer had been originally upgraded from NT to Win2000 and finally to XP.

One other reason this can occur is if the temporary file location references controlling the client machine TEMP environment variables are set to invalid or inaccessible locations.


Hopefully this is an exception, not the rule, and only happens on one or a few computers, otherwise finding out why Services Manager can't call an EXE from a path with long names, and or spaces in the path will be necessary.

Otherwise, if it is only one or a small number of computers then try importing into the computer the REG file contained in the zip file attached to this article, which will put in place all of the entries needed in order for the Altiris Agent to start as a service (this entry assumes the agent was installed to C:)  This import also changes the command line for the "ImagePath" string value and encapsulates it in double-quotes at the beginning and end.

The resolution to this problem is related to, and detailed in KB 17490. This KB also links to a Microsoft article relating to this problem.

If the issue involves TEMP variables, simply set the temporary (TEMP) drive letters and path to a functional location and restart the client machine. Default values for XP are shown below.

%USERPROFILE%\Local Settings\Temp

%USERPROFILE%\Local Settings\Temp



Applies To
Notification Server 6.0.6074

Attachments get_app